I lived in Phuket for 6 years. The diving is good and there is wide variety of accommodation and restaurants to suit all tastes. No problem with language, Thais are very friendly and understand much English. Visa wise you have to leave every 3 months even with an annual visa which can be annoying, though Penang is pretty nice to visit for a few days visa run.
That said I think if i'd had the choice I'd go for Bali. Better local diving options and easy hops to other places in Indonesia. The accommodation is, from what i could see from friend's places, better value than Phuket with more space and amenities. Local housekeepers are inexpensive too. Areas such as Sanur have a huge range of western food and very good local options, vibrant nightlife and welcoming community. If you have a vehicle there are shopping malls and supermarkets. traffic is a often an issue but it is easy to get around. Visa wise I believe you can apply for an annual retirement visa if you can show sufficient income (which i think $4000 will be no problem). Bahasa is relatively simple to learn, especially compared to Thai, but many people on Bali speak English very well.
I lived in the Philippines too but whilst most people speak English so that was easy, the food is not anywhere near as good as other asian countries (that was in 2010 though). Drinks are generally cheaper as the Philippines does not have such high alcohol tax as Thailand and Indonesia
Good luck.
